That's a real tough question. If the details aren't disclosed, the credit card company would have no right to enforce those details. For example, signing up for a credit card without an agreed-upon interest rate would mean there would mean neither party would have any moral standing either way as to what was owed.
If both parties agree to settle things in a court, and the court determines things by law, I would say that mandated credit card disclosures are a legitimate function of government.